The Millennium M10 home oxygen concentrator has the ability to deliver up to 10 liters of oxygen and has fewer parts. It is designed to be the most reliable while delivering the highest quality of oxygen. It has a twin head compressor, allowing this home oxygen concentrator to have a higher stroke for more airflow through the sieve beds. This Millennium M10 home oxygen concentrator is meant to run 24 hours a day. 7 days a week.